Who are the characters in The Art of the Commonplace?
Seeing as The Art of the Commonplace is a collection of essays on agrarianism, it does not have any characters. Author Wendell Berry does mention the influence of various people on how he came to live his agrarian lifestyle, but these essays focus more on groups of people and how society functions than on individuals. Berry writes in depth about how our use of land and resources has a connection to everything, ranging from racial inequality to the medical industry. He makes use of many references to historical figures and pieces of literature and culture, including works of Shakespeare and the Bible.
It's probably best to point out the likelihood that Berry's relationship with land is more influential on his life than his relationship with any one person.